Vitamin K antagonists and cognitive impairment: results from a cross-sectional pilot study among geriatric patients.

Background. Vitamin K is involved in brain physiology, suggesting that its deficiency induces cognitive decline. Our objective was to determine whether using vitamin K antagonists (VKAs) was associated with cognitive impairment among geriatric patients. Methods. Two hundred sixty-seven older patients (mean, 83.4 +/- 8.1 years; 56.9% female) were categorized according to cognitive impairment (ie, Mini-Mental State Examination <= 25). The regular use of VKAs was sought by questioning the patients, relatives, and family physicians. Age, gender, body mass index, comorbidity burden, mood and executive functioning, history of atrial fibrillation, ischemic stroke, intracranial hemorrhage and transient ischemic attack, use of other anticoagulants and antiplatelet medications, and severe renal failure were used as potential confounders. Results. Compared with participants without cognitive impairment (n = 70), those with Mini-Mental State Examination <= 25 used more frequently VKAs (p = .038). The risk of cognitive impairment was 15% higher with VKAs, specifically with fluindione. Using VKAs was independently associated with cognitive impairment (fully adjusted odds ratio = 17.4 [95% CI: 1.4-224.2], p = .028). Conclusions. We found more frequent cognitive impairment associated with the use of VKAs, specifically fluindione, among geriatric patients.